Cheap Outboard Spare Parts The crankshaft for outboard motor is a mechanical structure that transforms straight reciprocmotion into rotational motion. What does the crankshaft do for that matter? The most important function is to convert the heat energy burned by the gasoline in the outboard motor into the rotating mechanical kinetic energy through the connecting rod crank mechanism, output to the gearbox, and finally transfer the energy to the propeller to drive the outboard engine. The rotation of the crankshaft is the power source of the outboard engine, but also the source power of the whole outboard mechanical system, and is one of the core components of the outboard engine. The outboard crankshaft also lubricates the conveyor oil and coth connecting rod and piston pin.the crankshaft assy can balance the vibration of the outboard engine, transmit the speed and angle information of the crankshaft, that is, reflect the angle information of each cylinder, and drive other parts of the outboard motor to rotate. While the crankshaft is stirring the oil in the oil pan, cooling and scouring the crankshaft chamber, additionally lubricating the inside wall of the cylinder, the outboard engine internal heat through the splashing oil, through the oil pan and the outboard engine cylinder block.so the crankshaft assembly is one of the most important for outboard motor. CRANKSHAFT&PARTS Product NOProduct NameApplication 66T-11400-01CRANKSHAFT ASSYFOR YAMAHA 40HP (66T) 6F5-11400-01CRANKSHAFT ASSYFOR YAMAHA 40HP (6F5) 69P-11400-00CRANKSHAFT ASSYFOR YAMAHA 30HP 63V-11400-01CRANKSHAFT ASSYFOR YAMAHA 15HP (63V) 6B4-11400-00CRANKSHAFT ASSYFOR YAMAHA 15HP (6B4) 66T-11442-00CRANK 4FOR YAMAHA 40HP 66T 66T 11515-00SEAL, LABYRINTHFOR YAMAHA 40HP 66T 66T-11412-00CRANK 1FOR YAMAHA 40HP 66T 66T-11432-00CRANK 3FOR YAMAHA 40HP 66T 66T-11422-00CRANK 2FOR YAMAHA 40HP 66T 6F5-11422-11CRANK 2FOR YAMAHA 40HP 6F5 6F5-11432-11CRANK 3FOR YAMAHA 40HP 6F5 6F5-11442-11CRANK 4FOR YAMAHA 40HP 6F5 6F5-11412-11CRANK 1FOR YAMAHA 40HP 6F5 61N-11442-00CRANK 4FOR YAMAHA 30HP 61N-11515-00SEAL LABYRINTHFOR YAMAHA 30HP 61N-11422CRANK 2FOR YAMAHA 30HP 61N-11412-00CRANK 1FOR YAMAHA 30HP 61N-11432-00CRANK 3FOR YAMAHA 30HP 63V-11515-00SEAL LABYRINTHFOR YAMAHA 15HP 63V-11422-01CRANK 2FOR YAMAHA 15HP 63V-11432-02CRANK 3FOR YAMAHA 15HP 63V-11442-03CRANK 4FOR YAMAHA 15HP 63V11412-00CRANK 1FOR YAMAHA 15HP Cheap Outboard Spare Parts website:http://www.himarinepower.com/outboard-spare-parts/